This invention is directed to a bracket for mounting a sensor module to the outer end of a vehicle axle. The invention is particularly useful in mountng a magnetic wheel speed sensor module to a trailer axle inboard of a wheel hub rotatably mounted at that end of the axle.
Most vehicle anti-skid brake control systems function in response to electrical signals indicative of the angular velocity of one or more of the vehicle wheels. Generally these signals are derived from an electromagnetic sensor including a magnet carried by a stationary portion of the vehicle such as the axle housing, and a toothed or notched ring rotatable with the wheel opposite the magnet. As the teeth or notches of the ring pass the magnetic sensor unit the resulting variations in flux generate a signal, the frequency of which is a function of the angular velocity of the wheel.
To produce the required accuracy of the velocity signal the sensor unit and ring must be precisely located with respect to each other and must remain in a preselected relationship even after extended operation in which the components are subjected to road shocks and constant vibration. It is also essential that installation of the components be compatible with mass production techniques. The mounting of the sensor units must also be such that upon reinstallation of a wheel after removal for repair, the parts will automatically be restored to their original operating position.
Wheel speed sensor modules including means permitting automatic adjustment of the magnetic sensor units relative to a rotor are disclosed in U.S. Pat. No. 3,772,548 which issued to R. C. Wroblewski et al, on Nov. 13, 1973 and patent application Ser. No. 527,609, filed on Nov. 27, 1974, now U.S. Pat. No. 3,911,302. Those modules comprise magnetic sensor units which are movable relative to a supporting frame or housing.
The present invention provides a simple, economical and effective means for mounting a magnetic wheel speed sensor module to the axle of a vehicle.